The present invention relates to a power line for an electric vehicle.
Power lines for electric vehicles are known, which comprise a number of substantially flat conducting plates aligned in the traveling direction of the vehicle, substantially coplanar with a horizontal surface (e.g. a road surface), and separated by insulating elements. The conducting plates are connected in succession to a power supply source by a magnetic energizing signal supplied by the electric vehicle traveling along the power line, so the electric vehicle comprises a magnetic energizing member (e.g. a permanent magnet or electromagnet) for energizing the power line and so supplying the conducting plate, and at least one current pickup member for establishing a sliding electric contact with the live plate and picking up current by which to power the electric vehicle.
One example of a power line for an electric vehicle is described in European Patent Application EP 96113023.4, which relates to a power line in which a hollow elongated insulating enclosure is fitted on top with a number of conducting plates aligned in the traveling direction of the vehicle and separated by insulating elements interposed between adjacent conducting plates. The enclosure houses an elastically deformable strip conducting element, which extends in the traveling direction of the vehicle, comprises a strip portion made of ferromagnetic material, and is attracted by the magnetic field generated by electromagnets on the electric vehicle so as to flex a portion of the strip conducting element towards the conducting plates and so connect at least one conducting plate to a power line inside the enclosure. Another example of a power line for an electric vehicle is described in German Patent no 1.011.914 taken out by Ludwig Reihardt, published on Jul. 11, 1957, and in which an elongated insulating enclosure, closed at the top by a number of conducting plates aligned in a straight direction and insulated from one another, houses an elastically deformable strip conducting element made of ferromagnetic material, and which is attracted by the magnetic field generated by electromagnets to flex a portion of the strip conducting element towards the conducting plates to supply at least one of the plates.
The conducting plates are separated by spacer elements made of insulating material and arranged in the traveling direction of the electric vehicle, and are normally coplanar with a substantially horizontal surface, e.g. a road surface, made of nonconducting material (e.g. concrete). Lateral insulation of the plates, i.e. towards the road surface and crosswise to the traveling direction of the electric vehicle, is seriously compromised, however, in the event the road surface is covered with a thin layer of rainwater, in which case, potential decreases, on either side of the conducting plates and crosswise to the traveling direction of the electric vehicle, from a maximum at a live plate, to substantially zero at a distance of several meters from the live plate, thus seriously endangering anyone in the vicinity of the live plates. The main object of the present invention is to eliminate the aforementioned drawback.
Moreover, the strip conducting element of known power lines is attracted by a magnetic field directed by the electric vehicle through the conducting plates to the strip conducting element, the magnetic attraction of which is therefore at times weakened by the shielding effect of the conducting plates.
It is a further object of the present invention to provide a power line for an electric vehicle, which provides for eliminating any shielding effect of the plates, and so ensuring strong attraction of the strip conducting element.